This invention relates to sewing machines and, more particularly, to electronically controlled sewing machines.
Sewing machines employing sophisticated electronic technology for the storage and subsequent retrieval of stitch pattern information for a multiplicity of patterns have enjoyed great commercial success in recent years. One great advantage of the use of an electronically controlled sewing machine is in its simplicity of operation and control, as perceived by the user. With such a sewing machine, the user can select any one of a multiplicity of patterns by merely pushing a button. Additionally, with such a sewing machine, the user can alter the stitch pattern data that is stored in the sewing machine to control the size and/or shape of the selected pattern. For example, the user may vary the stitch length, vary the stitch width, sew a pattern having twice the length of the stored pattern, select a twin needle function for the sewing machine, etc. Additionally, it is known to provide the sewing machine with the capability of sewing the mirror image, in the direction of lateral needle jogging, of the selected pattern. This function may be accomplished by inverting the bight information with respect to the center needle position, as is well known in the art.
It would also be desirable to allow the user to sew the mirror image of a pattern in the feeding direction. Thus, for example, if a pattern of a train is provided in the sewing machine, with the train traveling along the direction of feed, by providing the "mirror feed" capability, the operator of the sewing machine could reverse the direction of travel of the train. In order to accomplish this, the stored stitch pattern data cannot be merely read in reverse. This is because, during the sewing operation, each stitch forming cycle consists of a needle penetration (bight) followed by cloth motion (feed). If the stitch pattern data were to be extracted from the memory in the reverse order of stitches and then stitches simply sewn with that order of data, the result would be an unrecognizable distortion of the pattern. Accordingly, it is an object of the present invention to provide a method and an arrangement operating in accordance therewith for sewing the mirror image of a stored pattern in the feeding direction.